1. Field of the Invention
This invention relates to textile fiber drafting aprons, as well as a method of manufacturing the aprons. Aprons of this type are used in the process known as drafting or texturing, in which bundles of discontinuous natural or synthetic fibers are passed between pairs of nearly contacting aprons which draws them out into long strands. These strands have superior physical characteristics, particularly increased tensile strength, and have uniform properties that enable them to be further used in textile processing.
2. Prior Art Statement
Conventional aprons are formed of two different elastomeric compounds, each formed into a separate layer and laminated together to form the finished product. Normally, the apron must be reinforced with cords located between the laminated layers and extending longitudinally of the circumference of the apron. It has also been known to reinforce aprons with fibrous materials in the two layers, and also to form the apron from a single layer of elastomeric material into which reinforcing fibers have been incorporated.
These prior art concepts are set forth in the following U.S. Patents:
Bacon, U.S. Pat. No. 2,362,340, Nov. 7, 1944 PA1 Howell, U.S. Pat. No. 3,011,221, Dec. 5, 1961 PA1 Meadows, U.S. Pat. No. 4,143,559, Mar. 13, 1979 PA1 Bendix Corporation Manual on Profilometer.RTM. Type VEG Model 22, Manual No. 70467307
The two layer reinforced cord construction is shown in the Howell Patent; the two layer fiber reinforcement in the Bacon patent; and the single layer fiber reinforcement in the Meadows et al patent. It should be noted that in all these prior art patents, the finished product must have a finish grinding operation on the outer surface in order to provide a desirable smooth surface for contacting the fibers being drafted. Thus, none of these patents suggest the concept of a non-reinforced, single layer apron having an unground fiber working surface. The Profilometer.RTM. is used to measure surface roughness as a comparison of the novel apron and standard aprons.